[IMPALA-8235] AdmissionControlTimeSinceLastUpdate TIME_MS counter breaks some profile consumers

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: Impala 3.2.0
• Fix Version/s: Impala 3.2.0
• Component/s: Backend
• Labels: observability
• Target Version: Impala 3.2.0
• Epic Color: ghx-label-6
• Assignee: Tim Armstrong
• Reporter: Tim Armstrong
• Created: 21/Feb/19 01:16
• Updated: 22/Feb/19 01:11
• Resolved: 22/Feb/19 01:11

Description

The issue is:

• type is a required field for TCounter with enum type TUnit
• Some readers (e.g. Java) that encounter an unknown enum value replace it it with null, then throw an exception because it is a required field

This means that the workflow for adding a new TUnit is basically broken, since we can't add a unit in Impala then update readers later.

I think we should switch to TIME_NS then reconsider the workflow here.

Issue Links

• is related to: IMPALA-8236 Adding new TUnit values to runtime profile is broken